Bumping BFQ patchset to v7r7.

4 files changed, 108 insertions, 70 deletions

diff --git a/0000_README b/0000_README
index c62fecfb..7c83fab5 100644
--- a/0000_README
+++ b/0000_README
@@ -111,14 +111,14 @@ Patch:  5000_enable-additional-cpu-optimizations-for-gcc.patch
 From:   https://github.com/graysky2/kernel_gcc_patch/
 Desc:   Kernel patch enables gcc optimizations for additional CPUs.
 
-Patch:  5001_block-cgroups-kconfig-build-bits-for-BFQ-v7r6-3.17.patch
+Patch:  5001_block-cgroups-kconfig-build-bits-for-BFQ-v7r7-3.17.patch
 From:   http://algo.ing.unimo.it/people/paolo/disk_sched/
-Desc:   BFQ v7r6 patch 1 for 3.17: Build, cgroups and kconfig bits
+Desc:   BFQ v7r7 patch 1 for 3.17: Build, cgroups and kconfig bits
 
-Patch:  5002_block-introduce-the-BFQ-v7r6-I-O-sched-for-3.17.patch
+Patch:  5002_block-introduce-the-BFQ-v7r7-I-O-sched-for-3.17.patch
 From:   http://algo.ing.unimo.it/people/paolo/disk_sched/
-Desc:   BFQ v7r6 patch 2 for 3.17: BFQ Scheduler
+Desc:   BFQ v7r7 patch 2 for 3.17: BFQ Scheduler
 
-Patch:  5003_block-bfq-add-Early-Queue-Merge-EQM-to-BFQ-v7r6-for-3.17.0.patch
+Patch:  5003_block-bfq-add-Early-Queue-Merge-EQM-to-BFQ-v7r7-for-3.17.0.patch
 From:   http://algo.ing.unimo.it/people/paolo/disk_sched/
-Desc:   BFQ v7r6 patch 3 for 3.17: Early Queue Merge (EQM)
+Desc:   BFQ v7r7 patch 3 for 3.17: Early Queue Merge (EQM)
diff --git a/5001_block-cgroups-kconfig-build-bits-for-BFQ-v7r6-3.17.patch b/5001_block-cgroups-kconfig-build-bits-for-BFQ-v7r7-3.17.patch
index fc428b81..b7065872 100644
--- a/5001_block-cgroups-kconfig-build-bits-for-BFQ-v7r6-3.17.patch
+++ b/5001_block-cgroups-kconfig-build-bits-for-BFQ-v7r7-3.17.patch
@@ -1,7 +1,7 @@
-From 09f6914bcd9af373e34215a711f36970f4c118ef Mon Sep 17 00:00:00 2001
+From fed943e59f99cb147eaa29462318c63c61d02153 Mon Sep 17 00:00:00 2001
 From: Paolo Valente <paolo.valente@unimore.it>
 Date: Thu, 22 May 2014 11:59:35 +0200
-Subject: [PATCH 1/3] block: cgroups, kconfig, build bits for BFQ-v7r6-3.17
+Subject: [PATCH 1/3] block: cgroups, kconfig, build bits for BFQ-v7r7-3.17
 
 Update Kconfig.iosched and do the related Makefile changes to include
 kernel configuration options for BFQ. Also add the bfqio controller
@@ -100,5 +100,5 @@ index 98c4f9b..13b010d 100644
  SUBSYS(perf_event)
  #endif
 -- 
-2.1.2
+2.1.3
 
diff --git a/5002_block-introduce-the-BFQ-v7r6-I-O-sched-for-3.17.patch1 b/5002_block-introduce-the-BFQ-v7r7-I-O-sched-for-3.17.patch1
index fba907ad..503e6641 100644
--- a/5002_block-introduce-the-BFQ-v7r6-I-O-sched-for-3.17.patch1
+++ b/5002_block-introduce-the-BFQ-v7r7-I-O-sched-for-3.17.patch1
@@ -1,9 +1,9 @@
-From dbb7d28e3809638f3732490a48d414171fd4186d Mon Sep 17 00:00:00 2001
+From 03c92eeb2016506fc4f475390da7798efbf02ef5 Mon Sep 17 00:00:00 2001
 From: Paolo Valente <paolo.valente@unimore.it>
 Date: Thu, 9 May 2013 19:10:02 +0200
-Subject: [PATCH 2/3] block: introduce the BFQ-v7r6 I/O sched for 3.17
+Subject: [PATCH 2/3] block: introduce the BFQ-v7r7 I/O sched for 3.17
 
-Add the BFQ-v7r6 I/O scheduler to 3.17.
+Add the BFQ-v7r7 I/O scheduler to 3.17.
 The general structure is borrowed from CFQ, as much of the code for
 handling I/O contexts. Over time, several useful features have been
 ported from CFQ as well (details in the changelog in README.BFQ). A
@@ -56,12 +56,12 @@ until it expires.
 Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
 Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
 ---
- block/bfq-cgroup.c  |  930 ++++++++++++
+ block/bfq-cgroup.c  |  936 ++++++++++++
  block/bfq-ioc.c     |   36 +
- block/bfq-iosched.c | 3887 +++++++++++++++++++++++++++++++++++++++++++++++++++
- block/bfq-sched.c   | 1207 ++++++++++++++++
- block/bfq.h         |  773 ++++++++++
- 5 files changed, 6833 insertions(+)
+ block/bfq-iosched.c | 3902 +++++++++++++++++++++++++++++++++++++++++++++++++++
+ block/bfq-sched.c   | 1214 ++++++++++++++++
+ block/bfq.h         |  775 ++++++++++
+ 5 files changed, 6863 insertions(+)
  create mode 100644 block/bfq-cgroup.c
  create mode 100644 block/bfq-ioc.c
  create mode 100644 block/bfq-iosched.c
@@ -70,10 +70,10 @@ Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
 
 diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
 new file mode 100644
-index 0000000..eb140eb
+index 0000000..11e2f1d
 --- /dev/null
 +++ b/block/bfq-cgroup.c
-@@ -0,0 +1,930 @@
+@@ -0,0 +1,936 @@
 +/*
 + * BFQ: CGROUPS support.
 + *
@@ -154,6 +154,12 @@ index 0000000..eb140eb
 +		entity->new_weight = bfq_ioprio_to_weight(bgrp->ioprio);
 +		entity->new_ioprio = bgrp->ioprio;
 +	} else {
++		if (bgrp->weight < BFQ_MIN_WEIGHT ||
++		    bgrp->weight > BFQ_MAX_WEIGHT) {
++			printk(KERN_CRIT "bfq_group_init_entity: "
++					 "bgrp->weight %d\n", bgrp->weight);
++			BUG();
++		}
 +		entity->new_weight = bgrp->weight;
 +		entity->new_ioprio = bfq_weight_to_ioprio(bgrp->weight);
 +	}
@@ -1048,10 +1054,10 @@ index 0000000..7f6b000
 +}
 diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
 new file mode 100644
-index 0000000..b919b03
+index 0000000..97ee934
 --- /dev/null
 +++ b/block/bfq-iosched.c
-@@ -0,0 +1,3887 @@
+@@ -0,0 +1,3902 @@
 +/*
 + * Budget Fair Queueing (BFQ) disk scheduler.
 + *
@@ -3730,7 +3736,7 @@ index 0000000..b919b03
 +	switch (ioprio_class) {
 +	default:
 +		dev_err(bfqq->bfqd->queue->backing_dev_info.dev,
-+			"bfq: bad prio %x\n", ioprio_class);
++			"bfq: bad prio class %d\n", ioprio_class);
 +	case IOPRIO_CLASS_NONE:
 +		/*
 +		 * No prio set, inherit CPU scheduling settings.
@@ -3753,6 +3759,13 @@ index 0000000..b919b03
 +		break;
 +	}
 +
++	if (bfqq->entity.new_ioprio < 0 ||
++	    bfqq->entity.new_ioprio >= IOPRIO_BE_NR) {
++		printk(KERN_CRIT "bfq_init_prio_data: new_ioprio %d\n",
++				 bfqq->entity.new_ioprio);
++		BUG();
++	}
++
 +	bfqq->entity.ioprio_changed = 1;
 +
 +	bfq_clear_bfqq_prio_changed(bfqq);
@@ -3869,14 +3882,13 @@ index 0000000..b919b03
 +
 +		if (bfqq != NULL) {
 +			bfq_init_bfqq(bfqd, bfqq, current->pid, is_sync);
++			bfq_init_prio_data(bfqq, bic);
++			bfq_init_entity(&bfqq->entity, bfqg);
 +			bfq_log_bfqq(bfqd, bfqq, "allocated");
 +		} else {
 +			bfqq = &bfqd->oom_bfqq;
 +			bfq_log_bfqq(bfqd, bfqq, "using oom bfqq");
 +		}
-+
-+		bfq_init_prio_data(bfqq, bic);
-+		bfq_init_entity(&bfqq->entity, bfqg);
 +	}
 +
 +	if (new_bfqq != NULL)
@@ -4533,6 +4545,14 @@ index 0000000..b919b03
 +	 */
 +	bfq_init_bfqq(bfqd, &bfqd->oom_bfqq, 1, 0);
 +	atomic_inc(&bfqd->oom_bfqq.ref);
++	bfqd->oom_bfqq.entity.new_ioprio = BFQ_DEFAULT_QUEUE_IOPRIO;
++	bfqd->oom_bfqq.entity.new_ioprio_class = IOPRIO_CLASS_BE;
++	/*
++	 * Trigger weight initialization, according to ioprio, at the
++	 * oom_bfqq's first activation. The oom_bfqq's ioprio and ioprio
++	 * class won't be changed any more.
++	 */
++	bfqd->oom_bfqq.entity.ioprio_changed = 1;
 +
 +	bfqd->queue = q;
 +
@@ -4548,6 +4568,7 @@ index 0000000..b919b03
 +	}
 +
 +	bfqd->root_group = bfqg;
++	bfq_init_entity(&bfqd->oom_bfqq.entity, bfqd->root_group);
 +#ifdef CONFIG_CGROUP_BFQIO
 +	bfqd->active_numerous_groups = 0;
 +#endif
@@ -4923,7 +4944,7 @@ index 0000000..b919b03
 +	device_speed_thresh[1] = (R_fast[1] + R_slow[1]) / 2;
 +
 +	elv_register(&iosched_bfq);
-+	pr_info("BFQ I/O-scheduler version: v7r6");
++	pr_info("BFQ I/O-scheduler version: v7r7");
 +
 +	return 0;
 +}
@@ -4941,10 +4962,10 @@ index 0000000..b919b03
 +MODULE_LICENSE("GPL");
 diff --git a/block/bfq-sched.c b/block/bfq-sched.c
 new file mode 100644
-index 0000000..c4831b7
+index 0000000..2931563
 --- /dev/null
 +++ b/block/bfq-sched.c
-@@ -0,0 +1,1207 @@
+@@ -0,0 +1,1214 @@
 +/*
 + * BFQ: Hierarchical B-WF2Q+ scheduler.
 + *
@@ -5573,6 +5594,13 @@ index 0000000..c4831b7
 +		old_st->wsum -= entity->weight;
 +
 +		if (entity->new_weight != entity->orig_weight) {
++			if (entity->new_weight < BFQ_MIN_WEIGHT ||
++			    entity->new_weight > BFQ_MAX_WEIGHT) {
++				printk(KERN_CRIT "update_weight_prio: "
++						 "new_weight %d\n",
++					entity->new_weight);
++				BUG();
++			}
 +			entity->orig_weight = entity->new_weight;
 +			entity->ioprio =
 +				bfq_weight_to_ioprio(entity->orig_weight);
@@ -6154,12 +6182,12 @@ index 0000000..c4831b7
 +}
 diff --git a/block/bfq.h b/block/bfq.h
 new file mode 100644
-index 0000000..d4b9470
+index 0000000..3e41f2d
 --- /dev/null
 +++ b/block/bfq.h
-@@ -0,0 +1,773 @@
+@@ -0,0 +1,775 @@
 +/*
-+ * BFQ-v7r6 for 3.17.0: data structures and common functions prototypes.
++ * BFQ-v7r7 for 3.17.0: data structures and common functions prototypes.
 + *
 + * Based on ideas and code from CFQ:
 + * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
@@ -6184,6 +6212,8 @@ index 0000000..d4b9470
 +#define BFQ_MIN_WEIGHT	1
 +#define BFQ_MAX_WEIGHT	1000
 +
++#define BFQ_DEFAULT_QUEUE_IOPRIO	4
++
 +#define BFQ_DEFAULT_GRP_WEIGHT	10
 +#define BFQ_DEFAULT_GRP_IOPRIO	0
 +#define BFQ_DEFAULT_GRP_CLASS	IOPRIO_CLASS_BE
@@ -6932,5 +6962,5 @@ index 0000000..d4b9470
 +
 +#endif /* _BFQ_H */
 -- 
-2.1.2
+2.1.3
 
diff --git a/5003_block-bfq-add-Early-Queue-Merge-EQM-to-BFQ-v7r6-for-3.17.0.patch b/5003_block-bfq-add-Early-Queue-Merge-EQM-to-BFQ-v7r7-for-3.17.0.patch
index 5f4e71b9..0b21a905 100644
--- a/5003_block-bfq-add-Early-Queue-Merge-EQM-to-BFQ-v7r6-for-3.17.0.patch
+++ b/5003_block-bfq-add-Early-Queue-Merge-EQM-to-BFQ-v7r7-for-3.17.0.patch
@@ -1,7 +1,7 @@
-From 596fb4db1452b42d366e54a1ac7902e9fb842643 Mon Sep 17 00:00:00 2001
+From 6b50a66488e742598f14a3fc906fe6a532854964 Mon Sep 17 00:00:00 2001
 From: Mauro Andreolini <mauro.andreolini@unimore.it>
-Date: Sun, 19 Oct 2014 01:15:59 +0200
-Subject: [PATCH 3/3] block, bfq: add Early Queue Merge (EQM) to BFQ-v7r6 for
+Date: Thu, 18 Dec 2014 21:52:54 +0100
+Subject: [PATCH 3/3] block, bfq: add Early Queue Merge (EQM) to BFQ-v7r7 for
  3.17.0
 
 A set of processes may happen  to  perform interleaved reads, i.e.,requests
@@ -34,13 +34,13 @@ Signed-off-by: Mauro Andreolini <mauro.andreolini@unimore.it>
 Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
 Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
 ---
- block/bfq-iosched.c | 743 +++++++++++++++++++++++++++++++++++++---------------
+ block/bfq-iosched.c | 751 +++++++++++++++++++++++++++++++++++++---------------
  block/bfq-sched.c   |  28 --
  block/bfq.h         |  54 +++-
- 3 files changed, 573 insertions(+), 252 deletions(-)
+ 3 files changed, 581 insertions(+), 252 deletions(-)
 
 diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
-index b919b03..bbfb4e1 100644
+index 97ee934..328f33c 100644
 --- a/block/bfq-iosched.c
 +++ b/block/bfq-iosched.c
 @@ -571,6 +571,57 @@ static inline unsigned int bfq_wr_duration(struct bfq_data *bfqd)
@@ -349,7 +349,7 @@ index b919b03..bbfb4e1 100644
  	if (bfqq == NULL || bfqq == cur_bfqq)
  		return NULL;
  
-@@ -1332,6 +1337,307 @@ static struct bfq_queue *bfq_close_cooperator(struct bfq_data *bfqd,
+@@ -1332,6 +1337,315 @@ static struct bfq_queue *bfq_close_cooperator(struct bfq_data *bfqd,
  	return bfqq;
  }
  
@@ -419,6 +419,13 @@ index b919b03..bbfb4e1 100644
 + * or with a close queue among the scheduled queues.
 + * Return NULL if no merge was scheduled, a pointer to the shared bfq_queue
 + * structure otherwise.
++ *
++ * The OOM queue is not allowed to participate to cooperation: in fact, since
++ * the requests temporarily redirected to the OOM queue could be redirected
++ * again to dedicated queues at any time, the state needed to correctly
++ * handle merging with the OOM queue would be quite complex and expensive
++ * to maintain. Besides, in such a critical condition as an out of memory,
++ * the benefits of queue merging may be little relevant, or even negligible.
 + */
 +static struct bfq_queue *
 +bfq_setup_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq,
@@ -429,13 +436,14 @@ index b919b03..bbfb4e1 100644
 +	if (bfqq->new_bfqq)
 +		return bfqq->new_bfqq;
 +
-+	if (!io_struct)
++	if (!io_struct || unlikely(bfqq == &bfqd->oom_bfqq))
 +		return NULL;
 +
 +	in_service_bfqq = bfqd->in_service_queue;
 +
 +	if (in_service_bfqq == NULL || in_service_bfqq == bfqq ||
-+	    !bfqd->in_service_bic)
++	    !bfqd->in_service_bic ||
++	    unlikely(in_service_bfqq == &bfqd->oom_bfqq))
 +		goto check_scheduled;
 +
 +	if (bfq_class_idle(in_service_bfqq) || bfq_class_idle(bfqq))
@@ -462,7 +470,7 @@ index b919b03..bbfb4e1 100644
 +check_scheduled:
 +	new_bfqq = bfq_close_cooperator(bfqd, bfqq,
 +					bfq_io_struct_pos(io_struct, request));
-+	if (new_bfqq)
++	if (new_bfqq && likely(new_bfqq != &bfqd->oom_bfqq))
 +		return bfq_setup_merge(bfqq, new_bfqq);
 +
 +	return NULL;
@@ -657,7 +665,7 @@ index b919b03..bbfb4e1 100644
  /*
   * If enough samples have been computed, return the current max budget
   * stored in bfqd, which is dynamically updated according to the
-@@ -1475,61 +1781,6 @@ static struct request *bfq_check_fifo(struct bfq_queue *bfqq)
+@@ -1475,61 +1789,6 @@ static struct request *bfq_check_fifo(struct bfq_queue *bfqq)
  	return rq;
  }
  
@@ -719,7 +727,7 @@ index b919b03..bbfb4e1 100644
  static inline unsigned long bfq_bfqq_budget_left(struct bfq_queue *bfqq)
  {
  	struct bfq_entity *entity = &bfqq->entity;
-@@ -2263,7 +2514,7 @@ static inline bool bfq_bfqq_must_idle(struct bfq_queue *bfqq)
+@@ -2263,7 +2522,7 @@ static inline bool bfq_bfqq_must_idle(struct bfq_queue *bfqq)
   */
  static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
  {
@@ -728,7 +736,7 @@ index b919b03..bbfb4e1 100644
  	struct request *next_rq;
  	enum bfqq_expiration reason = BFQ_BFQQ_BUDGET_TIMEOUT;
  
-@@ -2273,17 +2524,6 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
+@@ -2273,17 +2532,6 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
  
  	bfq_log_bfqq(bfqd, bfqq, "select_queue: already in-service queue");
  
@@ -746,7 +754,7 @@ index b919b03..bbfb4e1 100644
  	if (bfq_may_expire_for_budg_timeout(bfqq) &&
  	    !timer_pending(&bfqd->idle_slice_timer) &&
  	    !bfq_bfqq_must_idle(bfqq))
-@@ -2322,10 +2562,7 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
+@@ -2322,10 +2570,7 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
  				bfq_clear_bfqq_wait_request(bfqq);
  				del_timer(&bfqd->idle_slice_timer);
  			}
@@ -758,7 +766,7 @@ index b919b03..bbfb4e1 100644
  		}
  	}
  
-@@ -2334,40 +2571,30 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
+@@ -2334,40 +2579,30 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
  	 * in flight (possibly waiting for a completion) or is idling for a
  	 * new request, then keep it.
  	 */
@@ -806,7 +814,7 @@ index b919b03..bbfb4e1 100644
  			jiffies_to_msecs(bfqq->wr_cur_max_time),
  			bfqq->wr_coeff,
  			bfqq->entity.weight, bfqq->entity.orig_weight);
-@@ -2376,12 +2603,16 @@ static void bfq_update_wr_data(struct bfq_data *bfqd,
+@@ -2376,12 +2611,16 @@ static void bfq_update_wr_data(struct bfq_data *bfqd,
  		       entity->orig_weight * bfqq->wr_coeff);
  		if (entity->ioprio_changed)
  			bfq_log_bfqq(bfqd, bfqq, "WARN: pending prio change");
@@ -824,7 +832,7 @@ index b919b03..bbfb4e1 100644
  		    time_is_before_jiffies(bfqq->last_wr_start_finish +
  					   bfqq->wr_cur_max_time)) {
  			bfqq->last_wr_start_finish = jiffies;
-@@ -2390,11 +2621,13 @@ static void bfq_update_wr_data(struct bfq_data *bfqd,
+@@ -2390,11 +2629,13 @@ static void bfq_update_wr_data(struct bfq_data *bfqd,
  				     bfqq->last_wr_start_finish,
  				     jiffies_to_msecs(bfqq->wr_cur_max_time));
  			bfq_bfqq_end_wr(bfqq);
@@ -841,7 +849,7 @@ index b919b03..bbfb4e1 100644
  }
  
  /*
-@@ -2642,6 +2875,25 @@ static inline void bfq_init_icq(struct io_cq *icq)
+@@ -2642,6 +2883,25 @@ static inline void bfq_init_icq(struct io_cq *icq)
  	struct bfq_io_cq *bic = icq_to_bic(icq);
  
  	bic->ttime.last_end_request = jiffies;
@@ -867,7 +875,7 @@ index b919b03..bbfb4e1 100644
  }
  
  static void bfq_exit_icq(struct io_cq *icq)
-@@ -2655,6 +2907,13 @@ static void bfq_exit_icq(struct io_cq *icq)
+@@ -2655,6 +2915,13 @@ static void bfq_exit_icq(struct io_cq *icq)
  	}
  
  	if (bic->bfqq[BLK_RW_SYNC]) {
@@ -881,7 +889,7 @@ index b919b03..bbfb4e1 100644
  		bfq_exit_bfqq(bfqd, bic->bfqq[BLK_RW_SYNC]);
  		bic->bfqq[BLK_RW_SYNC] = NULL;
  	}
-@@ -2944,6 +3203,10 @@ static void bfq_update_idle_window(struct bfq_data *bfqd,
+@@ -2950,6 +3217,10 @@ static void bfq_update_idle_window(struct bfq_data *bfqd,
  	if (!bfq_bfqq_sync(bfqq) || bfq_class_idle(bfqq))
  		return;
  
@@ -892,7 +900,7 @@ index b919b03..bbfb4e1 100644
  	enable_idle = bfq_bfqq_idle_window(bfqq);
  
  	if (atomic_read(&bic->icq.ioc->active_ref) == 0 ||
-@@ -2991,6 +3254,7 @@ static void bfq_rq_enqueued(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+@@ -2997,6 +3268,7 @@ static void bfq_rq_enqueued(struct bfq_data *bfqd, struct bfq_queue *bfqq,
  	if (bfqq->entity.service > bfq_max_budget(bfqd) / 8 ||
  	    !BFQQ_SEEKY(bfqq))
  		bfq_update_idle_window(bfqd, bfqq, bic);
@@ -900,7 +908,7 @@ index b919b03..bbfb4e1 100644
  
  	bfq_log_bfqq(bfqd, bfqq,
  		     "rq_enqueued: idle_window=%d (seeky %d, mean %llu)",
-@@ -3051,13 +3315,49 @@ static void bfq_rq_enqueued(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+@@ -3057,13 +3329,49 @@ static void bfq_rq_enqueued(struct bfq_data *bfqd, struct bfq_queue *bfqq,
  static void bfq_insert_request(struct request_queue *q, struct request *rq)
  {
  	struct bfq_data *bfqd = q->elevator->elevator_data;
@@ -951,7 +959,7 @@ index b919b03..bbfb4e1 100644
  	rq->fifo_time = jiffies + bfqd->bfq_fifo_expire[rq_is_sync(rq)];
  	list_add_tail(&rq->queuelist, &bfqq->fifo);
  
-@@ -3222,18 +3522,6 @@ static void bfq_put_request(struct request *rq)
+@@ -3228,18 +3536,6 @@ static void bfq_put_request(struct request *rq)
  	}
  }
  
@@ -970,7 +978,7 @@ index b919b03..bbfb4e1 100644
  /*
   * Returns NULL if a new bfqq should be allocated, or the old bfqq if this
   * was the last process referring to said bfqq.
-@@ -3242,6 +3530,9 @@ static struct bfq_queue *
+@@ -3248,6 +3544,9 @@ static struct bfq_queue *
  bfq_split_bfqq(struct bfq_io_cq *bic, struct bfq_queue *bfqq)
  {
  	bfq_log_bfqq(bfqq->bfqd, bfqq, "splitting queue");
@@ -980,7 +988,7 @@ index b919b03..bbfb4e1 100644
  	if (bfqq_process_refs(bfqq) == 1) {
  		bfqq->pid = current->pid;
  		bfq_clear_bfqq_coop(bfqq);
-@@ -3270,6 +3561,7 @@ static int bfq_set_request(struct request_queue *q, struct request *rq,
+@@ -3276,6 +3575,7 @@ static int bfq_set_request(struct request_queue *q, struct request *rq,
  	struct bfq_queue *bfqq;
  	struct bfq_group *bfqg;
  	unsigned long flags;
@@ -988,7 +996,7 @@ index b919b03..bbfb4e1 100644
  
  	might_sleep_if(gfp_mask & __GFP_WAIT);
  
-@@ -3287,25 +3579,26 @@ new_queue:
+@@ -3293,25 +3593,26 @@ new_queue:
  	if (bfqq == NULL || bfqq == &bfqd->oom_bfqq) {
  		bfqq = bfq_get_queue(bfqd, bfqg, is_sync, bic, gfp_mask);
  		bic_set_bfqq(bic, bfqq, is_sync);
@@ -1027,7 +1035,7 @@ index b919b03..bbfb4e1 100644
  	}
  
  	bfqq->allocated[rw]++;
-@@ -3316,6 +3609,26 @@ new_queue:
+@@ -3322,6 +3623,26 @@ new_queue:
  	rq->elv.priv[0] = bic;
  	rq->elv.priv[1] = bfqq;
  
@@ -1038,7 +1046,7 @@ index b919b03..bbfb4e1 100644
 +	 * queue has just been split, mark a flag so that the
 +	 * information is available to the other scheduler hooks.
 +	 */
-+	if (bfqq_process_refs(bfqq) == 1) {
++	if (likely(bfqq != &bfqd->oom_bfqq) && bfqq_process_refs(bfqq) == 1) {
 +		bfqq->bic = bic;
 +		if (split) {
 +			bfq_mark_bfqq_just_split(bfqq);
@@ -1055,10 +1063,10 @@ index b919b03..bbfb4e1 100644
  
  	return 0;
 diff --git a/block/bfq-sched.c b/block/bfq-sched.c
-index c4831b7..546a254 100644
+index 2931563..6764a7e 100644
 --- a/block/bfq-sched.c
 +++ b/block/bfq-sched.c
-@@ -1084,34 +1084,6 @@ static struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd)
+@@ -1091,34 +1091,6 @@ static struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd)
  	return bfqq;
  }
  
@@ -1094,10 +1102,10 @@ index c4831b7..546a254 100644
  {
  	if (bfqd->in_service_bic != NULL) {
 diff --git a/block/bfq.h b/block/bfq.h
-index d4b9470..0093084 100644
+index 3e41f2d..e5f4001 100644
 --- a/block/bfq.h
 +++ b/block/bfq.h
-@@ -216,18 +216,21 @@ struct bfq_group;
+@@ -218,18 +218,21 @@ struct bfq_group;
   *                      idle @bfq_queue with no outstanding requests, then
   *                      the task associated with the queue it is deemed as
   *                      soft real-time (see the comments to the function
@@ -1125,7 +1133,7 @@ index d4b9470..0093084 100644
   * All the fields are protected by the queue lock of the containing bfqd.
   */
  struct bfq_queue {
-@@ -267,6 +270,7 @@ struct bfq_queue {
+@@ -269,6 +272,7 @@ struct bfq_queue {
  	unsigned int requests_within_timer;
  
  	pid_t pid;
@@ -1133,7 +1141,7 @@ index d4b9470..0093084 100644
  
  	/* weight-raising fields */
  	unsigned long wr_cur_max_time;
-@@ -296,12 +300,42 @@ struct bfq_ttime {
+@@ -298,12 +302,42 @@ struct bfq_ttime {
   * @icq: associated io_cq structure
   * @bfqq: array of two process queues, the sync and the async
   * @ttime: associated @bfq_ttime struct
@@ -1176,7 +1184,7 @@ index d4b9470..0093084 100644
  };
  
  enum bfq_device_speed {
-@@ -537,7 +571,7 @@ enum bfqq_state_flags {
+@@ -539,7 +573,7 @@ enum bfqq_state_flags {
  	BFQ_BFQQ_FLAG_prio_changed,	/* task priority has changed */
  	BFQ_BFQQ_FLAG_sync,		/* synchronous queue */
  	BFQ_BFQQ_FLAG_budget_new,	/* no completion with this budget */
@@ -1185,7 +1193,7 @@ index d4b9470..0093084 100644
  					 * bfqq has timed-out at least once
  					 * having consumed at most 2/10 of
  					 * its budget
-@@ -550,12 +584,13 @@ enum bfqq_state_flags {
+@@ -552,12 +586,13 @@ enum bfqq_state_flags {
  					 * bfqq has proved to be slow and
  					 * seeky until budget timeout
  					 */
@@ -1201,7 +1209,7 @@ index d4b9470..0093084 100644
  };
  
  #define BFQ_BFQQ_FNS(name)						\
-@@ -585,6 +620,7 @@ BFQ_BFQQ_FNS(in_large_burst);
+@@ -587,6 +622,7 @@ BFQ_BFQQ_FNS(in_large_burst);
  BFQ_BFQQ_FNS(constantly_seeky);
  BFQ_BFQQ_FNS(coop);
  BFQ_BFQQ_FNS(split_coop);
@@ -1210,5 +1218,5 @@ index d4b9470..0093084 100644
  #undef BFQ_BFQQ_FNS
  
 -- 
-2.1.2
+2.1.3